What is the difference between _url and _path while using the routes in rails

I had the same question and I wrote a small post about this in my blog

The reason is summarized here (I found this on a forum):

*_path are for views because ahrefs are implicitly linked to the current URL. So it’d be a waste of bytes to repeat it over and over. In the controller, though, *_url is needed for redirect_to because the HTTP specification mandates that the Location: header in 3xx redirects is a complete URL.

Here is another explanation which says it depends on whether we need to use an absolute URI when linking to an SSL site from a non-SSL site, and vice versa.

What I have read so far, doesn't suggest that any of them is more secure than the other. It really comes down to what is the "proper" usage.

path is relative while url is absolute.

An example of the difference for a resource called "user":

users_url # => http://localhost:3000/users
users_path  # => /users

Same answer as Petros, except that modern browsers handle relative redirects just fine. (I'd comment on his answer, but I can't yet.)

By secure if you mean not exposing all the data passed, then _path is better as it generates a relative url, something like '/login' but _path would give 'http://localhost:3000/login'. Please refer to this blog post i found sometime back regarding the same. When _url is better than _path

_url will give the entire path. As it contains the domain name and protocol, you can use it for eg. to send email or redirecting to another domain, etc.

_path will return the path which is after '/' without domain,protocol etc. So you can use it every now and then(I guess), where you don't require details of domain.

The _url helper generates a string containing the entire URL, while the _path helper generates a string containing the relative path from the root of the application, e.g.:

photos_url  # => "http://www.example.com/photos"
photos_path # => "/photos"

As per Rails Guides - Routing.